[jQuery] Once hidden elements no longer report values

I have built a contact form that appears using lightbox at the
following site:

http://www.dassant.com/

The jquery in question can be found here

http://www.dassant.com/_scripts/mailer.js

The .val() of the input fields gives me nothing, although it seems
that I can toggle them on and off in the form. Why aren't they
reporting their values?